1 Answers
Modified-release dosage is a mechanism that delivers a drug with a delay after its administration or for a prolonged period of time dosage] or to a specific target in the body.
Sustained-release dosage forms are dosage forms designed to release a drug at a predetermined rate in order to maintain a constant drug concentration for a specific period of time with minimum side effects. This can be achieved through a variety of formulations, including liposomes and drug-polymer conjugates. Sustained release's definition is more akin to a "controlled release" rather than "sustained".
Extended-release dosage consists of either sustained-release or controlled-release dosage. SR maintains drug release over a sustained period but not at a constant rate. CR maintains drug release over a sustained period at a nearly constant rate.
Sometimes these and other terms are treated as synonyms, but the United States Food and Drug Administration has in fact defined most of these as different concepts. Sometimes the term "depot tablet" is used by non-native speakers, but this is not found in any English dictionaries and is a literal translation of the term used in Swedish and some other languages.